The Tokyo Olympics will now take place between July 23 and August 8 next year.
The decision was announced by the head of the Tokyo 2020 organising committee on Monday.
"The schedule for the games is key to preparing for the games," Yoshiro Mori said. "This will only accelerate our progress."
He added that the Paralympic Games will run from August 24 to September 5.
The decision to postpone the sporting event was taken over concerns surrounding the coronavirus epidemic.